what role do decomposers play in the nitrogen cycle?

Most of the nitrogen in soils and biota originated in the atmosphere and has accumulated over the millions of years in which nitrogen fixation has been taking place. Much of the terrestrial fixation is carried out by symbiotic bacteria in plant roots and to a lesser extent by free living soil bacteria. Specialised, widespread soil bacteria play vital roles in nitrification ( oxidation of the ammonium compounds produced by decomposition to nitrate). Some bacteria oxidise ammoniumions to nitrite, and others complete the process by converting NO2 to nitrate. These chemoautotrophs obtain energy from such transformations.Denitrifying bacteria reduce nitrate to gaseous nitrogen in anaerobic conditions, returning a small proporation of that circulating in the biosphere to atmosphere.

Decomposers convert the nitrogen found in other organisms into ammonia and return it to the soil. A few of these type of bacteria return nitrogen to the atmosphere by a process called denitrification, however this amount is small.

the whole nitrogen cycle is:

Organisms require nitrogen to produce amino acids. Nitrogen makes up seventy-eight percent of the atmosphere, but most organisms can not use this form of nitrogen, and must have the fixed form. The nitrogen cycle produces the fixed form of nitrogen these organisms need.

Step 1: A special type of bacteria called nitrogen fixing bacteria take in atmospheric nitrogen and produceammonia (NH3).

Step 2: Other bacteria use this ammonia to produce nitrates and nitrites, which are nitrogen and oxygen containing compounds.

Step 3: The nitrates and nitrites are used by plants to make amino acids which are then used to make plant proteins.

Step 4: Plants are consumed by other organisms which use the plant amino acids to make their own.

Step 5: DECOMPOSERS convert the nitrogen found in other organisms into ammonia and return it to the soil. A few of these type of bacteria return nitrogen to the atmosphere by a process called denitrification, however this amount is small.